Phase-Coherent Astrometric Interferometry

摘要

This effort constituted the second stage in the development of the Mark III stellar interferometer, which is a fringe-tracking long-baseline Michelson interferometer designed primarily for wide angle astrometry at the milliarc-second level. Stellar diameters were also measured. The instrument is installed on Mount Wilson in California; it is a joint project between the Massachusetts Institute of Technology, the Smithsonian Astrophysical Observatory, the Naval Research Laboratory, and the U.S. Naval Observatory. The instrument employs a two-color technique to reduce errors due to atmospheric turbulence, and its various baselines are laser-monitored to achieve high precision. The instrument can operate with four possible baseline configurations from 9 m NE-SW to 20 m N-S. Most observations have been made with the 12-m N-S baseline. (MJM)